From attacking scientists and destroying labs to desecrating graves and intimidating staff, militant animal rights activists are prepared to do anything to further their cause. How do they justify their actions? Are they freedom fighters or terrorists?

Is the age of cheap oil about to come to an end? According to many experts, we are about to reach the point of "peak oil" -- the level at which supply can no longer keep up with demand. This, say the doomsayers, could send economies spinning into turmoil and up-end our comfortable, urban lifestyles. But others claim predictions like this are simply scaremongering. They believe supply will match demand for decades to come. So who's telling the truth? 'Peak Oil' investigates.